Temple-Baraitser syndrome: a rare and possibly unrecognized condition.

Temple-Baraitser syndrome, previously described in two unrelated patients, is the association of severe mental retardation and abnormal thumbs and great toes. We report two additional unrelated patients with Temple-Baraitser syndrome, review clinical and radiological features of previously reported cases and discuss mode of inheritance. Patients share a consistent pattern of anomalies: hypo or aplasia of the thumb and great toe nails and broadening and/or elongation of the thumbs and halluces, which have a tubular aspect. All patients were born to unrelated parents and occurred as a single occurrence in multiple sibships, suggesting sporadic inheritance from a de novo mutation mechanism. Comparative genomic hybridization in Patients 1, 2 and 3 did not reveal any copy number variations. We confirm that Temple-Baraitser syndrome represents a distinct syndrome, probably unrecognized, possibly caused by a de novo mutation in a not yet identified gene.